# What's the strange iron/sulfur smell from forced air duct?

**URL:** <https://boards.straightdope.com/t/whats-the-strange-iron-sulfur-smell-from-forced-air-duct/347898>\
**Category:** Factual Questions\
**Created:** [March 11, 2006, 12:52am UTC](https://boards.straightdope.com/t/whats-the-strange-iron-sulfur-smell-from-forced-air-duct/347898 "2006-03-11T00:52:25Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![CC](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@CC](https://boards.straightdope.com/u/CC)\
**Post date:** [March 11, 2006, 12:52am UTC](https://boards.straightdope.com/t/whats-the-strange-iron-sulfur-smell-from-forced-air-duct/347898/1 "2006-03-11T00:52:25Z")

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It’s an electric heat, forced air system. I’ve been noticing a peculiar smell in one room when the heat’s on. Sort of an irony - sulfur smell. Maybe the heating element is burning out? But I don’t smell it at any of the other duct outlets, leading me to think something might be in the duct. But it’s such a subtle odor - not as if something has crawled in there and died. Is my best bet to get one of those duct cleaner services? Where do I start trying to diagnose this thing? Any ideas on what it might be?